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Author:
yetzen (CA)
I have a hot water slab leak near the hot water tank. After cutting off the leaking branch (above the slab) and capped both ends of the cut, water still leaks from the slab when turning on the cold inlet to the hot water tank.
When the hot water tank inlet is shut off, water also leaks when cloth washer is turned on (for cold only).
I am stumped as to where the source of water is from. Any suggestions? Thanks.
(The hot water tank has a recirculating loop with a pump and a check valve.)
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Author:
packy (MA)
i'm guessing you need to shut off the recirculating loop..
shutting it at the tank should do it...
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Author:
hj (AZ)
Are you sure you cut the right pipe? It acts like the recirculation line is the leaking one, and since the hot and cold water at the washer are NOT interconnected, I cannot imagine how it leaks when that is used.
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Author:
bernabeu (SC)
they MAY be interconnected IN the washer through the dual solenoid mixer while the washer is 'filling'
juuuust a possibility
==============================================
"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638
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Author:
hj (AZ)
Two reasons what that cannot happen.
1. The valves are pilot operated in most cases so they need water pressure to open, and
2. They "interconnect" through an open "Y" connection so there is NO WAY for back pressure to occur.
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Author:
yetzen (CA)
Following your suggestion I blocked the recirculating pump with a blank washer. Turning on the cold water supply to the hot water heater still caused the same slab leak to appear, although the intensity might have been reduced.
Since the house has two opposite wings served by one hot water heater and one recirculating pump, could there be two parallel return branches in the recirculating loop that feeds the leak?
Thanks for all comments.
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Author:
packy (MA)
2 seperate returns joined inside the wall is a definite possibility.
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Author:
hj (AZ)
Blocking the pump, does not stop the flow through the circulation line unless you also disconnect it at the other end. You could have two circulation lines, but they should not be connected together in a "hidden" location since proper usage requires that the have provision to control the two flows to balance them.
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Author:
yetzen (CA)
hj and packy:
You are right that the recirculating loop most likely has two branches in parallel and they are connected at some "hidden" places with no adjustment for balancing. After breaking the hot water supply line feeding most of the house,leaving only one bathroom connected, the leak stopped. Thanks for your comments.
Now a second question. How important are the deburring and insulation for new copper pipes (hot only), now the house needs to be re-piped?
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